The present invention relates generally to improvements in controllable supports for precision optical components, and more particularly to a novel actuator for precisely controlling the contour of a mirrored surface, and to an improved mirror structure incorporating the novel actuator.
Mirrors included in the optical trains of precision optical systems may be subject to substantial forces tending to impair the utility of the optical system. For example, mirrors used to define the optical resonant cavity of a laser system, or to define an optical train in the utilization of the laser output, may be subject to severe thermal or pressure induced stresses which distort the reflective surface of the mirror. Accordingly, it may be highly desirable to provide means adjacent such a mirror to modify the shape of the reflective surface of the mirror in controlled manner whereby a predetermined mirrored surface contour may be maintained.
The present invention provides an novel actuator for precisely controlling the contour of a mirrored surface supported on a thin mirror faceplate, whereby a predetermined mirrored contour may be maintained against the influence of thermal or pressure effects, or may be selectively and precisely changed in a programmed, preselected manner. The actuator of the present invention may be utilized in conjunction with a suitable mirrored faceplate to selectively introduce optical path differences of dimensions in the optical wavelength range over the surface of the faceplate to compensate for optical path difference errors in the wave front incident on the mirror resulting from distortions of the mirrored surface. The actuator comprises a magnet and coil, operatively connected by way of a web of stabilizing flexures to an actuating rod in contact with the rear surface of a mirrored faceplate. The position of the actuator rod may be precisely controlled through electrical signals to the coil. A position sensor monitors the position of the actuator rod.
It is, therefore, a principal object of the present invention to provide an actuator for precisely controlling the contour of a mirrored surface.
It is a further object of the invention to provide an improved optical mirror having precision controllable contour.
These and other objects of the present invention will become apparent as the detailed description of certain representative embodiments thereof proceeds.